Home lock not working either.
So I looked at all the DJI videos on the subject, first, of course.
Then I did a subject search here, So now I started this thread.

Ok, so I have tried multiple times to get into Course Lock or Home Lock, but they never work. When I push forward on the stick the craft still follows the front of the craft not the direction of where I was traveling.

So I know how Home and Course lock are supposed to work. In Course lock mode it flys in a Grid pattern, once you lock it in it is supposed to continue forward on the course you started it on, REGARDLESS of the Yaw position of the craft ,,right?
Home lock, the craft (PH2) will return towards the home position radially, like the spokes on a wheel, if you push forward on the stick it goes away from you, if you pull back it comes back to home, REGARDLESS of the Yaw position of the craft, right?

Update, ok, so I have a Mac, and I have the Software Assistant for Mac v.1.08 the latest version.
It works fine, I have done a complete update of all the drivers and stuff for the whole shebang, no problems.
Did a complete recalibration and it worked fine, flies fine.
Green lights all go ahead.

So when I go to the main 'View' page on the PT2 Software Assistant there is a place that shows the status of the IOC mode. (intelligent orientation control) so it shows that it is 'OFF'. In the first place , why? And there is no place to click on to turn it on.
So how do I turn it on using the Software Assistant for Mac? Anyone know? I know that Dronefly uses Mac'shttps://www.youtube.com/watch?v=FYvk5sTcbpQ
I used that video for recalibration, it worked great, a one minute video that gets to the point.

In my case (Walkera QRX 350) the battery voltage is critical. When the volts are getting low, the GPS functions do not engage.

My experiments to date have been restricted to Position Hold and I am becoming confident with this after a few "hairy" moments (but no damage).

I usually know that things are not quite right by testing the arm and disarm function, at the end of my pre-flight test I have learned not to attempt to fly with GPS if the motors will arm in the RTH position. Sometimes they arm in the "Position hold" position. I used to attempt position hold in that condition. The result was that it locked altitude but did not "position" lock.

Ok, I found out how, for Mac, you open up the PT2 Software Assistant for the phantom, you have to be 'online', turn on your Radio controller first, then power up your PT2, then you hook up the PT2 with the supplied USB to USB Mini cable then go the main 'View' page and in the upper right corner there is a gray button that says 'Phantom' , click it, (that activates NAZA M, mode) then click yes to every other window that asks you if you really want to switch to 'Naza M' Mode. Click Yes.

So then go to the Advanced tab and click the box for Enabling IOC. now you are set. Make sure your lowest atti position is set at 'FailSafe'. There is more to , I just can't remember it all, but you want to do a power cycle when you are all done.
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So, they keep this a secret 'cause you can now set it in fully manual mode which enables you to be able 'Flip and Roll' the craft. So now you are in Advanced Mode

My experiments have shown that GPS devices may be quite critical of battery voltage and battery condition. It could be that we all need to move up to the new, highest, quality levels.

Yesterday I discovered that one of my batteries (bought recently in a batch of three, from a famous maker) consistently puts my GPS into the danger zone, sometimes when fully charged at 12.6v; and often when slightly discharged at 12.3v.

It looks just like the others and has been used just as much. It works perfectly for a full duration in the manual functions of this quad and has never shown any problem in non-GPS quads; but it is now marked as U/S for GPS flights. I have noticed that this battery, at the end of a flight, often shows one cell as being .2 of a volt below its brothers. That is an important detail to watch. (I always do balanced charging.)

All of the batteries perform this way when the total voltage goes below 11.1.

The lesson I learn from this is that flights demanding GPS need to be conducted in the early moments of the battery's use. It also leads me to think that 3 cell Li-po batteries, with 2,200mah, are a bit small for energetic GPS Quadcopters.

Thanks Pete, well I have the new Phantom2 for GoPro(PT2), and it has battery power indicator bars, 4 for full battery.
When my PT2 has gone into a wobble I have had 3 bars, 2 bars and 1.5 bars.
According to the manual, 1.5 bars has 25 to 35% of power left in the battery.
So you would think that the Voltage regulator would be well designed enough to draw and invert the neccesary voltage to deliver the proper amperage to the system, so that none of these problems occur.???

Especially at 2 or more bars indicating on the intellibattery the PT2 uses

I am getting low stress flights (just cruising really) of around 9 minutes duration without any sense of alarm from the flight controller. Alarm in this case means a forced landing. This has happened twice and is quite spectacular but safe. However I would much prefer an audio alarm with one safe minute to run. I guess that at big flying clubs, audio alerts could be stressful for too many pilots.